University green stormwater infrastructure

Project update

November 16, 2018

Project public outreach, alternatives analysis phase

In September and October, King County conducted public outreach to share information about the project and request input on community values around green stormwater infrastructure benefits and challenges, and the balance of benefits and costs - benefits that the project will consider when choosing how and where to install GSI in the area.

Respondents were asked to share feedback on their priorities in a survey for a variety of benefits and challenges factored by the County in the definition of alternatives. This feedback is currently informing the definition and selection of a preferred alternative, which the County plans to share with the community in early 2019.

Outreach snapshot

A media release and a flier mailed to residents, property owners, and businesses in the Project Study Area encouraged them to visit an online open house or attend an open house in their neighborhood to learn about the project and respond to a priorities questionnaire. Outreach events included three weekday evening drop-in sessions and one all-day Saturday drop-in open house at convenient neighborhood locations within the Project Study Area. In addition, social media notifications were posted by partnering community organizations.

Project description

King County is beginning a green stormwater infrastructure project in north Seattle. This project will install facilities to help control a combined sewer overflow in Portage Bay. In 2017-18, the project team will study soil, groundwater, surface water flow, and street conditions in the project area to identify the best locations for facilities to be installed.

In this first phase of the project the County will consider what types of green stormwater infrastructure it should build, and where within the study area they should be installed. Some options include different types of bioretention and permeable pavement in alleys or streets. Learn more!

Project study area

The project will select sites for installing green stormwater infrastructure from within the area below.

Approximate boundaries are intended for planning purposes only. Further study and evaluation will be completed prior to selection of any site.

Project need

In the University CSO Basin in Seattle, heavy rains can cause sewers to overflow into Portage Bay approximately six times per year. This project will install facilities to help control these overflows. Learn more about King County’s CSOs.

What is green stormwater infrastructure?

Green stormwater infrastructure—also called natural drainage—mimics nature by slowing or reducing polluted runoff close to its source. It also treats polluted runoff from roads, roofs, and parking lots by capturing and cleaning it before it harms our waterways. Learn more!

Your feedback

The County will share its evaluation of two to four alternative ways of doing green stormwater infrastructure with the public, and ask for your feedback online and through community events. Visit the public involvement page.

Project schedule

4Q 2017

Alternative analysis begins

Early action project schedule

While construction for this GSI project will take place in 2021-23 (see left), the County plans to install early action projects in 2020.

Many residents of this area can install their own green stormwater infrastructure (rain gardens and cisterns) on their own property funded by an average $4,400 rebate. Check your eligibility and learn more .